[llvm] [GVN] Permit load PRE to happen in more cases (PR #76063)

[David Sherwood via llvm-commits]

david-arm wrote:

@nikic So perhaps I've misunderstood what this comment in the code above means:

```
  // Check to see how many predecessors have the loaded value fully
  // available.
  MapVector<BasicBlock *, Value *> PredLoads;
```

I took that to mean that `PredLoads` contains the loads from all predecessors that are fully available.

https://github.com/llvm/llvm-project/pull/76063